In their article "4-(Indolyl-3)-1-(benzimidazolonylalkyl)-piperidines, a Novel Group of Potential Antiallergy Compounds", Arzneim.-Forsch, 35 (1), 272-276 (1985), Freter et al. disclose compounds of the formula: ##STR2##
as anti-allergy agents by virtue of their histamine H1-blocking actions in addition to weak mast cell stabilizing properties.